Tidal power or ‘tidal energy’ is a form of hydropower that requires significant tidal differences. Tidal power is inextricably linked to the sun and moon as their gravitational pull is the largest influence on the regularity of the tides which is what tidal energy is drawn from. The sun and moon’s gravitational pull and the predictability of the tides make tidal energy an inexhaustible form of renewable energy which has been used in various forms since the Roman times. When the high tide makes its way to the shoreline, water is trapped in reservoirs or river estuaries and stored behind dams or barrages. When the tide recedes, sluices
containing turbines control the release of the water trapped behind them, generating electricity. Free-standing water turbines are now being used more frequently in many narrow tidal channels and work under the same premise as the sluices, however the free-standing water turbines can be used with both flows of the tides instead of just the ebb of the tide.
Wave energy, which is created by the contact of winds with the ocean surface, has a wider geographic application than any of the other forms of ocean renewable energy. While it is not as commonly used as other forms of ocean energy because it is not as regular and predictable as tidal power, it can generate a constant flow of energy when harnessed efficiently. Machines that are able to harvest wave energy are known as wave energy converters (WECs). The level of wave power generated by such devices is determined by the height, length, speed and density of the waves.
The large waves that make their way across to the north Atlantic build up enormous amounts of energy travelling towards to west coast of Ireland. Harnessing this vast amount of renewable energy means that Ireland has the potential to be one of the market leaders in the wave energy sector due to the advantage of its geographical location. With the operation of the Ocean Energy Development Strategy
also in place, Ireland could further increase the breadth and depth of its investment in research and innovation and at the same time effectively reduce its reliance on fossil fuels and create a cleaner energy product. WECs that have already been moored off the West Coast of Ireland include Wavebob and OE Buoy.